Fluid dispensing closures for squeeze-type container applications typically are of one-piece integrally molded construction of relatively inexpensive plastic such as polyolefin, typically polypropylene or a polyethylene such as low density polyethylene. However, in many fluid dispensing applications, it is desirable to minimize or eliminate contact between the fluid and polyolefin material to avoid selective adsorption of materials to the polyolefin. It has been proposed in U.S. Pat. No. 3,227,332 to provide a three-piece dispensing closure that includes a shell of polystyrene, an insert of a less rigid more resilient material such as polyethylene, and a separate polyethylene overcap. The insert has a flange that extends along the undersurface of the shell for sealing engagement with the end surface of a container neck finish. However, the insert material and construction do not address or overcome the above-mentioned need in the art.
The present disclosure embodies a number of aspects that can be implemented separately from or in combination with each other.
A dispensing closure, in accordance with one aspect of the present disclosure, includes a closure shell of plastic construction having a skirt for mounting on a container neck finish. An insert of plastic construction different from and more rigid than the shell includes a mid portion mounted to the shell, a base with the skirt for sealing engagement with a container neck finish when the closure is mounted on the neck finish, a tip extending from the mid portion and a through-passage for dispensing product from within the container. An overcap is provided for removable receipt over the tip, and preferably is of one-piece integrally molded construction with the shell and flexibly tethered to the shell. The base of the insert preferably is constructed for sealing engagement with the inside surface of the container neck finish, the end surface of the container neck finish and/or the outside edge of the container neck finish.
A dispensing closure in accordance with another aspect of the disclosure includes a closure shell of plastic construction having a skirt for mounting the closure to a container neck finish. An insert of plastic construction different from the shell has a mid portion mounted to the shell, a base within the skirt for plug-sealing engagement within a container neck finish when the shell is mounted on the container neck finish, a tip extending from the mid portion of the insert and a through-passage for dispensing product from within the container. An overcap is provided for removable receipt over the tip. The insert base preferably has an upwardly concave part-toroidal flange for sealing engagement with the inside surface of the container neck finish when the closure is mounted to the container neck finish. The flange preferably has an outside diameter greater than the inside diameter of the container neck finish so that the flange is force-fit within the container neck finish as the closure is applied to the neck finish. The overcap preferably is of integrally molded construction with the closure shell and connected to the closure shell by a flexible tether. The overcap may be adapted for snap-receipt on the insert tip or on a portion of the closure shell surrounding the insert tip.